1. Technical Field
The present invention relates to printed circuit boards in general, and in particular to a method and apparatus for aligning surface mounted devices on a printed circuit board. Still more particularly, the present invention relates to a method and apparatus for aligning surface mounted semiconductor optoelectric devices on a printed circuit board within an optoelectric computer system.
2. Description of the Prior Art
Within most computer systems, a bus (or a group of buses) is typically the primary vehicle by which communication among electronic components takes place. Although there are different types of buses, in its most basic form, each bus is simply a series of electrical wires interconnecting various electronic components within a computer system. The electrical transmission characteristics of a bus are defined by the material properties of the bus, the physical geometry of the components, the clock speed of the signals, and the noise within the bus. Thus, both the limitations in materials and the limitations in electronic components contribute to the electrical transmission characteristics of a bus.
As computer systems become more complex, there is a continuing need to drive signals within a bus at a faster clock rate while at the same time minimizing power, noise, and electromagnetic interference. Most if not all of these requirements are satisfied by optoelectric computer systems. An optoelectric computer system is a computer system in which digital data signals are transmitted in both electrically conductive buses and optical buses (or pathways). Such computer systems may, for example, utilize semiconductor devices that have vertical cavity surface emitting lasers (VCSELs) serving as transducers for optoelectric exchange. One such semiconductor device that is now in commercial use is the HFBR-5303 VCSEL transceiver manufactured by Hewlett Packard.TM..
Because the diameter of the optical pathways located on the printed circuit board of an optoelectric computer system are generally very small, it is important to ensure that surface mounted optoelectric devices, as they are mounted on the printed circuit board during the assembly process, are sufficiently aligned with the optical pathways to permit optical signal communication. In view of such, the present disclosure provides a method and apparatus for aligning surface mounted optoelectric devices on a printed circuit board such that reliable operation can be assured.